Respiratory syncytial virus (RSV): For health professionals
On this page
- Key information
- Transmission
- Clinical manifestations
- Diagnosis
- Treatment
- Prevention and control
- Surveillance
Key information
RSV is an enveloped RNA virus. It causes seasonal epidemics of respiratory illness in countries around the world. In Canada, elevated RSV activity generally takes place from late fall to early spring. Different regions in Canada have different timing and length of the RSV season.
RSV is a common illness and the most common cause of lower respiratory tract illness in young children everywhere. Most children will experience RSV infections by the age of 2.
Reinfection with RSV can reoccur throughout life, and repeat infections are often less severe in adulthood. Medical conditions or older age put people at risk of severe disease.
Primary infection with RSV can present as:
- upper respiratory tract illness
- lower respiratory tract disease
- pneumonia
- bronchiolitis
- tracheobronchitis
The risk of severe outcomes from RSV infection is higher among:
- infants and young children under the age of 2
- infants whose transportation for severe RSV disease treatment is complex, and/or whose risk of severe RSV disease intersects with established social and structural health determinants such as those experienced by some Indigenous communities across First Nations, Métis and Inuit populations
- children with chronic lung disease, congenital heart disease, compromised immune systems or neuromuscular disorders
- adults with chronic lung or heart disease or compromised immune systems
- older adults
In severe cases, RSV requires hospitalization and may be life-threatening. In children, hospitalization rates are highest among children under 1 year old, and especially within the first 6 months of life. In adults, hospitalization is highest in the oldest adults and those with certain chronic medical conditions.
Transmission
Humans are the only source of RSV infection. Transmission occurs from respiratory particles containing the virus and from contact with contaminated surfaces. A person is infectious for about 8 days on average, with a range of 1 to 21 days. The incubation period is sometimes longer in some infants and people with weakened immune systems.
Clinical manifestations
The incubation period of RSV ranges from 2 to 8 days. Common clinical presentations can include:
- rhinorrhea
- coughing
- sneezing
- headache
- fatigue
- fever
- wheezing
- pharyngitis
- bronchiolitis
In infants, the only symptoms of RSV may be:
- decreased activity
- difficulty breathing
- difficulty feeding
- irritability
Severe infection from RSV is more common among:
- infants and young children
- immunocompromised individuals
- older adults with certain chronic conditions, such as:
- asthma
- diabetes
- cardiovascular disease
- chronic obstructive pulmonary disease (COPD)
Diagnosis
In most outpatient settings, the diagnosis is clinical, and specific laboratory testing is not done. Often a person admitted to hospital is tested with a nasopharyngeal swab for RSV.
Treatment
There is no specific antiviral treatment for RSV. Most healthy children and adults will recover on their own in 1 to 2 weeks. Most treatment for RSV is to address symptoms and provide supportive care.
Over-the-counter medications, such as acetaminophen or ibuprofen, can be given to relieve the symptoms associated with RSV, such as fever. Drinking plenty of fluids and getting adequate rest is strongly encouraged.
People with severe RSV may need to be admitted to the hospital for oxygen and supportive care.
Prevention and control
Immunization
The most effective way to prevent RSV transmission is through immunization.
There are 4 immunization products that are approved to prevent RSV disease in infants.
- Palivizumab/Synagis (AstraZeneca) is a monoclonal antibody that has been authorized in Canada for decades and is given monthly to infants at high risk of severe RSV disease.
- This product may be phased out in most jurisdictions.
- Clesrovimab/Enflonsia (Merck) is a long-acting monoclonal antibody authorized to protect all infants in their first RSV season.
- Nirsevimab/Beyfortus (Sanofi) is a long-acting monoclonal antibody authorized to protect all infants in their first RSV season and high-risk children in their second RSV season.
- RSVpreF/Abrysvo (Pfizer) is a vaccine that is given during pregnancy to prevent RSV disease in infants.
These products are not used to treat infants who already have RSV. Rarely would more than one product be needed to protect an infant from RSV.
All of the above are passive immunization products, meaning that infants are protected by either directly receiving a monoclonal antibody (palivizumab, clesrovimab or nirsevimab) or by transplacental transfer of antibodies during pregnancy (RSVpreF).
For adults, there are 3 vaccines (RSVPreF3, RSVpreF and mRNA-1345) approved to prevent severe RSV for those 60 years and older. One of these (RSVPreF3) is also approved to prevent severe RSV for those 50 to 59 years of age at high risk. Two of these vaccines (RSVpreF and mRNA-1345) are also approved for adults 18 through 59 years of age who are at increased risk for lower respiratory tract disease.
- RSVpreF/Abrysvo (Pfizer)
- RSVPreF3/Arexvy (GSK)
- mResvia/mRNA-1345 (Moderna)
Learn more:
- Respiratory syncytial virus vaccines: Canadian Immunization Guide
- Respiratory syncytial virus statements: National Advisory Committee on Immunization
- Routine Practices and Additional Precautions for Preventing the Transmission of Infection in Healthcare Settings Guideline
Personal protective measures
Health care providers can also encourage the use of personal protective measures to reduce the risk of getting or spreading RSV and other respiratory infectious diseases, such as influenza and COVID-19, which include:
- staying home when sick or infected
- wearing a well-constructed, well-fitting mask when appropriate
- improving indoor ventilation when possible
- cleaning hands regularly
- covering coughs and sneezes
- regularly cleaning and disinfecting high-touch surfaces and objects
Respiratory infectious diseases: Reduce your risk with personal protective measures
Surveillance
FluWatch+ surveillance
FluWatch+ is Canada's national surveillance system that monitors the spread of respiratory viruses, such as:
- RSV
- COVID-19
- flu (influenza)
- other respiratory viruses
The FluWatch+ surveillance system has an interactive dashboard. This technical dashboard provides a weekly overview of key trends on the activity of respiratory viruses.
Learn more:
International surveillance
The World Health Organization (WHO) has current international respiratory activity data.